Stabilized mineral oil compositions



United States Patent Office 3,249,541 STABILIZED MINERAL OIL COMPOSITIONS Paul Y. C. Gee, Woodbury, and Harry J. Andress, J12, Pitman, N.J., assignors to Socony Mobil Oil Company, Inc., a corporation of New York No Drawing. Filed Dec. 23, 1963, Ser. No. 332,855 14 Claims. (Cl. 25233.6)

This invention relates to stabilized mineral oil compositions and, more particularly, to mineral oil compositions adapted for use as fuel oils containing certain additives to inhibit the presence of sediment during prolonged periods of storage and to prevent screen-clogging and rusting of ferrous metal surfaces. The invention, furthermore, relates to mineral oil compositions adapted for use as lubricating oils containing the aforementioned additives as rust-inhibitors, which, aside from imparting such desired properties to fuel oils and lubricating oils, also inhibit such fuel oils and lubricating oils against undesirable emulsification.

It is well known to those skilled in the art that the aforementioned fuel oils are prone to form sludge or sediment during prolonged periods of storage. The formation of such sediment has an adverse effect on burner operation, by reason of its tendency to clog screens and nozzles. In addition to sediment, which is formed during storage, most fuel oils contain other impurities, such as rust, dirt and entrained water. Such impurities tend to settle out on equipment parts, such as nozzles, screens, filters and other parts, thereby also clogging them and causing the equipment to fail or perform unsatisfactorily. Another factor, incident to the storage and handling of fuel oils, is the breathing of storage vessels. This condition results in the accumulation of considerable quantities of Water in the tanks or fuels, which creates rusting problems. Thereafter, when the oil is removed for transportation such large amounts of water may be carried along as to cause rusting of ferrous metal surfaces in pipelines, tankers and the like.

In the past, it has been the practice toovercome the aforementioned difficulties by employing a separate additive for each condition encountered, i.e., a sediment inhibitor, an anti-screen clogging agent and an antirust agent. The use of several additives, however, results in problems of additive compatibility, thus restricting the choice .of additive combinations. In addition, the use of a plurality of additives tends to unduly increase the cost of the fuel.

It is also well known to those skilled in the art that the rusting of ferrous metal surfaces has long been a common occurrence in the field of lubrication, and particu larly so in steam turbine lubrication during the initial operation of new installations. Rusting is most pronounced at points where the clearance between bearing surfaces is very small, as, for example, in governor mechanisms. This is usually caused by water entering the oil supply, as a result of condensation and entrainment in the oil throughout the circulating system, and thus coming into contact with the ferrous metal surfaces. As in the case of fuel oils, emulsification of the oil is also objectionable in lubricating oils, and, in the case of turbine lubricating oils, is particularly objectionable in that the desired degree of lubrication for metal parts in contact with the emulsified oil, is reduced.

It is, therefore, an object of the present invention to provide a new class of additives for incorporation in mineral oil compositions which are useful as fuel oils and lubricating oils, obviating the disadvantages heretofore encountered in compositions of this type.

Another object of the invention is to provide new and improved stabilized mineral oil compositions containing the aforementioned additives, and which are useful as fuel oils and lubricating oils.

3,249,541 Patented May 3, 1966 Other objects and advantages inherent in the invention will become apparent to those skilled in the art from the following detailed description.

It has noW been found that the aforementioned problems heretofore encountered in the use of mineral oil compositions, such as fuel oils and lubricating oils, can be obviated by the use of a single additive composition. In general, as more fully hereinafter disclosed, the present invention relates to mineral oil compositions containing a small amount, sufficient to provide the aforementioned improvements, of a metal salt of maleamic acid and a mixture of aliphatic hydrocarbyl primary branched-chain amines having from about 4 to about 30 carbon atoms per molecule.

The aforementioned mixtures of aliphatic hydrocarbyl primary branched-chain amines having about 4 to about 30 carbon atoms per molecule employed in forming the metal salts of maleamic acid therewith, comprise, in general, the tertiary-alkyl primary mono-amines in which a carbon atom of a tertiary-alkyl group is attached to the amino group and which have from about 4 to about 30 carbon atoms, and preferably from about 12 to about 24 carbon atoms, per molecule. Thus, these amines contain the group:

Non-limiting examples of these amine reactants are t-butyl amine, t-hexyl primary amine, n-octenylamine, toctyl primary amine, t-decyl primary amine, t-dodecyl primary amine, t-tetradecyl primary amine, t-octadecyl primary amine, t-eicosyl primary amine, t-docosyl primary amine, t-tetracosyl primary amine, and t-triacontyl primary amine. The amine reactants can be prepared in several ways well known to those skilled in the art. The metal of the metal salts of the additive compositions of the present invention, is a divalent metal, and, preferably, includes magnesium, barium, calcium, zinc and strontium, although other divalent metals may also be employed.

The metal salts are prepared, in general, by first reacting one mole of the aforementioned aliphatic primary amines with one mole maleic anhydride at a temperature within the range from about 65 C. to about C., for a period of from about 1 to about 3 hours. The resulting amine amic acid is next heated with the appropriate divalent metal, (e.g. a Group II metal), in the form of a metal alkoxide, or metal hydroxide, or, if so desired, by the use of an alkali metal hydroxide and double displacement with, for example, a Group II metal halide, (e.g., zinc chloride). The normal metal salts are prepared by heating two moles of the aforementioned amine amic acid with one mole of the metal alkoxide or metal hydroxide, for example, magnesium methoxide or magnesium hydroxide. The alkoxy metal salts are prepared by heating one mole of the aforementioned amine amic acids with one mole of metal alkoxide, for example, magnesium rnethoxide.

The fuel oils that are improved in accordance with this invention are hydrocarbon fractions having an initial boiling point of at least about 100 F. and an end boiling point no higher than about 750 F., and boiling substantially continuously throughout their distillation range. Such fuel oils are generally known as distillate fuel oils. It is to be understood, however, that this term is not restricted to straight-run distillate fractions. The distillate fuel oils can be straight-run distillatefuel oils, catalytically or thermally cracked (including hydrocracked) distillate fuel oils, or mixtures of straight-run distillate fuel oils, naphthas and the like with cracked distillate fuel stocks. Moreover, such fuel oils can be treated in accordance with well known commercial methods, such as, acid or caustic treatment, hydrogenation, solvent refining, clay treatment, etc.

The distillate fuel oils are characterized by their relatively low viscosities, pour points, and the like. The principal property which characterizes the contemplated hydrocarbons, however, is the distillate range. As mentioned hereinbefore, this range will lie between about 100 F. and about 750 F. Obviously, the distillate range of each individual fuel oil will cover a narrower boiling range falling, nevertheless, within the above-specified limits. Likewise, each fuel oil will boil substantially continuously throughout its distillation range.

Particularly contemplated among the fuel oils are Nos. 1, 2, and 3 fuel oils used in heating and as Diesel fuel oils, and the jet combustion fuels. The domestic fuel oils generally conform to the specifications set forth in ASTM Specifications D396-48T. Specifications for Diesel fuels are defined in ASTM Specifications D975-48T. Typical jet fuels are defined in Military Specification MIL-F-5624B. The amount of the metal salt of maleamic acid and the aforementioned amines that is added to the distillate fuel oil in accordance with this invention will depend, of course, upon the intended purpose and the particular metal salt selected, as they are not all equivalent in their activities. Some may have to be used in greater concentrations than others to be effective. In most cases, in which it is desired to obtain all of the aforesaid beneficial results, additive concentrations varying between 10 pounds per thousand barrels of oil and about 200 pounds per thousand barrels of oil will be employed. It may not always be desired, however, to accomplish all of the aforementioned results. In such cases, where it is desired to effect only one or two results, lower concentrations can be used. Thus, if it is desired only to prevent rust under dynamic conditions, as in a pipeline, it has been found that concentrations as low as about 5 p.p.m., i.e., about one pound of additive per thousand barrels of oil, are effective. In general, therefore, the amount of metal salt of maleamic acid and the aforementioned amines that can be added to the distillate fuel oil, in order to achieve a beneficial result, will vary generally between about one pound per thousand barrels of oil and about 200 pounds per thousand barrels of oil. Preferably, it will vary between about and about 200 pounds per thousand barrels of oil.

If it is desired, the fuel oil compositions can contain other additives for the purpose of achieving other results. Thus, for example, there can be present foam inhibitors and ignition and burning quality improvers. Examples of such additives are silioones, dinitropropane, amyl nitrate, metal sulfonates, and the like.

In reference to the aspect of this invention relating to lubricating oils, the additives embodied for use are effective to impart anti-rust properties while also inhibiting emulsification and, particularly, to impart such properties to highly refined mineral lubricating oils for use in steam turbines. For such usage, the additive embodied herein can be used in amounts that can vary over a rather wide range, based on the weight of the lubricating oil but, generally, in an amount of from about 0.001 to ten percent and, preferably, between about 0.05 and about one percent. If desired, other substances can be added to the lubricating oil to impart other properties and, for example, anti-oxidants, pour point depressants, V.I. improvers, extreme pressure agents, etc.

Thus, the improving agents of this invention are useful for various petroleum fractions in concentrations ranging from about 0.001% up to about ten percent based on the weight of the fraction with the actual concentration used being dependent on the particular oil fraction (fuel oil or lubricating oil) and the use for which the improving agent is intended.

The following specific examples are for the purpose of illustrating the mineral oil compositions of this invention, and of exemplifying the specific nature thereof. It is to be strictly understood, however, that this invention is not to be limited by the particular additives and mineral oils, or to the operations and manipulations described therein. Other salts of maleamic acid and other amines of the aforementioned types, as well as other mineral oils, as discussed hereinbefore, can be used, as those skilled in the art will readily appreciate.

The amine reactants, Primene 81R and Primene JMT, used in the specific working Examples 1 through 10 are mixtures of pure amines. Primene 81R is a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino (--NH group and containing 12 to 15 carbon atoms per amine molecule. This mixture contains, by weight, about 85 percent tertiarydodecyl primary amine, about 10 percent tertiary-pentadecyl primary amine, and relatively small amounts i.e., less than 5 percent of amines having less than 12 or more than 15 carbon atoms. Primene JMT is a mixture of tertiary-alkyl primary amines containing 18 to 24 carbons, having a tertiary carbon atom attached to the NH group, and containing, by weight, about 40 percent tertiary-octadecyl primary amine, about 30 percent tertiary-eicosyl primary amine, about 15 percent tertiarydocosyl primary amine, about 10 percent tertiary-tetracosyl primary amine, and a small amount, less than 5 percent, other amines as high as tertiary-triacontyl primary amine. In Example 11 there is shown that the metal salts of maleamic acid prepared from primary straight-chain amines (rather than from the primary branched-chain amines of the present invention) are unsatisfactory as fuel additives, since they are found to develope undesirable, heavy emulsions with water in fuels; whereas the metal salts of the primary branched-chain maleamic acids of the present invention do not form such emulsions. In Examples 11 Armeen 12D, is a mixture of primary straight-chain amines containing, approximately, by weight, 2 percent decylamine, percent dodecylamine, and 3 percent tetradecylamine.

EXAMPLE 1 A mixture of 49 gms. (0.5 mole) of maleic anhydride, gms. (0.5 mole) of Primene 81R and 310 gms. of xylene as diluent was stirred at 95-100 C. for two hours to form the Primene 81R maleamic acid. The Primene 81R maleamic acid was then added at room temperature with stirring to 6.1 gms. (0.25 mole) of magnesium in the form of a magnesium methylate solution. The mixture was gradually heated to C. and was held at 125 C. until the methanol stopped coming over. The reaction product was filtered through Hyflo clay. The final product, the magnesium salt of Primene 81R maleamic acid, which contained 66 /3% xylene, was clear and fluid at room temperature.

A mixture of 49 gms. (0.5 mole) of maleic anhydride, gms. (0.5 mole) of Primene JMT and 410 gms. of

- Process oil #5 (a conventional parafiin oil having a viscosity of 100 S.U.S. at 100 F). as diluent was stirred at 95-100 C. for two hours to form the Primene J MT maleamic acid. The Primene IMTv maleamic acid was then added at room temperature with stirring to 6.1 gms. (0.25 mole) of magnesium in the form of a magnesium methylate solution. The mixture, heated gradually with stirring to distill out the methanol, 'became viscous at 100 C. A quantity of 20 cc. of distilled water added dropwise made the mixture'fiuid again. The temperature was gradually raised to C. and held at 175 C. for 30 minutes; The reaction product was filtered through Hyfio clay easily. The final product, the magnesium salt of Primene 5 J MT maleamic acid, which contained 66% Process oil, was clear and fluid at room temperature.

6 EXAMPLE 6 A mixture of 49 gms. (0.5 mole) of maleic anhydride 150 gms. (0.5 mole) of Primene JMT and 215 gms. of

Analysis I Estlmated i Found Process oil #5 was stirred at 95 C. for 2 hours to form Percent Mg 1 0 94 the Primene JMT maleamic acid. To the Primene JMT Percent NQIIIII IIIIIIIIIIII 1:1 1:05 maleamic acid was added at room tfihlperahlfe with Stirring 20 gms. (0.5 mole) of sodium hydroxide previously dissolved in 300 cc. of methanol. The mixture was gradu- EXAMPLE 3 ally heated to 150 C. to form a sodium salt. To the A mixture of 49 gms. (0.5 mole) of maleic anhydride, sodium salt was added at room temperature with stirring 100 gms. (0.5 mole) of Primene 81R and 183 gms. of 34 gms. (0.25 mole) of zinc chloride previously dissolved Xylene as diluent was stirred at 95 C. for 2 hours to form in 200 cc. of methanol. The mixture was gradually heatthe Primene 81R maleamic acid. To the Primene 81R ed to 150 C. and held at 150 C. for 2 hours. The reacmaleamic acid was added at room temperature with stirtion product was permitted to settle and filtered through ring 34.34 gms. (0.25 mole) of barium in the form of a Hyflo clay. The final product, the zinc salt of Primene barium methylate solution. The mixture was gradually JMT maleamic acid, which contained 50% Process oil heated to 140 C. to distill out the methanol. The reac- #5, was clear and fluid at room temperature. tion product, being viscous, was diluted with 366 gms. of xylene and filtered through Hyflo clay. The final product, the barium salt of Primene 81R maleamic acid, which Analysls Estimated Found contained 75% xylene, was clear and fluid at room tem- Percent Zn 42 perature. Percent N 1. 6 1. 47

Analysis Estimated Found EXAMPLE 7 Percent Ba u 523 A mixture of 49 gms. (0.5 mole) of maleic anhydride, PercentN 1.0 1.13 100 gms. (0.5 mole) of Primene 81R and 100 cc. of xylene as diluent was stirred at 95 C. for 2 hours to form EXAMPLE 4 the Primene 81R maleamic acid. To the Primene 81R 3O maleamic acid was added at room temperature with stir- A mixture of 49 mole) of malelc ahhydrlde, ring 20 gms. (0.5 mole) of sodium hydroxide previously 150 g H1016) 0f Primene JMT and 233 of dissolved in 300 cc. of methanol. The mixture was gradu- Process oil #5 as diluent was stirred at 95 C. for 2 n hated to to f a Sodium Salt To the hours to form the Primene JMT maleamic acid- To The sodium salt was added at room temperature with stirring Primene 1 MT maleamic acid was added at room 27.75 gms. (0.25 mole) of CaCl previously dissolved in hlfe with Stirring 34-34 g mole) of barium 111 200 cc. of methanol. The mixture was gradually heated the form of a barium methylate solution. The mixture to 42 C, and held at 142 C, f r one h h was gradually heated to 150 C. to distill out the methtion product, being Viscous, was diluted with 500 f anol. The reaction product, being viscous, was diluted benzene filt d through Hyfl l and distilled to 150 with 233 E 0f Process Oil and filtered through C. under house vacuum. The final product, the calcium Hyflo clay- The final Product, the barium Salt of salt of Primene 81R maleamic acid, which weighed 158 mene JMT maleamic acid, which contained 66%% Pr C- gyms, theory 159 gms., was diluted With 316 gms. of ess oil #5, was clear and fluid at room temperature. Xylene.

Analysis Estimated Found Analysis Estimated Found Percent Ba 4. 9 4. 86 Percent Ca 2.1 1.8 Percent N 1. 0 0. 91 Percent N 1. 4 1. 41

EXAMPLE 5 EXAMPLE 8 A mixture of 49 Thole) of maleic anhydride, A mixture of 49 gms. (0.5 mole) of maleic anhydride, 100 gIhS- 111016) of Primene 81R and 150 of. 150 gms. (0.5 mole) of Primene JMT and 209 gms. of Xylene as diluent was Stirred at 2 hours to Process oil #5 was stirred at 95 C. for 2 hours to form form the Primene 81R maleamic acid. To the Primene the Primene JMT maleamic acid To the Primene T 81R maleamic acid was added at room temperature with 1 i id was dd at room temperature with i Stirring 20 111016) of NaOH p y ring 20 gms. (0.5 mole) of sodium hydroxide previously Solved in 300 0f Inethalloh The mixture was dissolved in 300 cc. of methanol. The mixture was grady heated to to form a Sodium Salt- T0 the ually heated to C. to form a sodium salt. To the sodium salt was added at room temperature with stirring 60 sodium salt was gradually added at room temperature 34 H1016) of Zinc chloride Previously diswith stirring 27.75 gms. (0.25 mole) of calcium chloridesolved in 200 cc. of methanol. The mixture was gradupreviously di l d i 200 of h L Th i ally heated to 140 C. and Was held at 140 C- fo 2 ture was gradually heated to 145 C. to form a calcium hours to insure the complete formation of the zinc salt. alt and wa held at 145 C, for one hour. The reaction The reaction product was diluted with 400 cc. of benzene, 65 product, being viscous, was diluted with 209 gms. of Procfiltered through Hyflo clay and distilled to C. under ess oil #5 and filtered through Hyflo clay. The final house vacuum. The final product, the zinc salt of Priroduct, the calcium salt of Primene JMT maleamic acid, mene 81R maleamic acid, which weight 150 gms., theory which contained 66 /s% Process oil #5, was clear and gms., was diluted with 158 gms. of xylene. fluid at room temperature.

Analysis Estimated Found Analysis Estimated Found Percent Zn 5.0 4. 56 Percent Ca 1.6 1. 4 Percent N 2. 2 1. 96 Percent N 1. 1 1. 03 75 EXAMPLE 9 A mixture of 49 grns. (0.5 mole) of maleic anhydride and 150 gms. (0.5 mole) of Primene JMT diluted with 422 gms. of Process oil was stirred at 95 C. for 2 hours to form the Primene J MT maleamic acid. To the Primene J MT maleamic acid was added at room temperature with stirring 12.16 gms. (0.5 mole) of magnesium in the formof a magnesium methylate solution. The mixture, being heated gradually with stirring to distill out the methanol, became viscous at 85 C. A quantity of 9 cc. of water added dropwise made the mixture fluid again. The temperature was gradually raised to 150 C. and was held at 150 C. for one hour. The reaction product was then filtered through Hyflo clay. The final product, the methoxy magnesium salt of Primene JMT Estimated Found Analysis 320640 F. boiling range] Percent Mg. 1. 92 1. 84 Cone, Screen Percent N-.- 1.01 1.03 Inhibitor lb./1,000 Clogging,

bbls. percent XAMPLE 0 E 1 Uninhibited fuelblend 0 100- A mixture of 24.5 gms. (0.25 mole) of maleie anhygninliiglgeguelgleng plusgx. 2g T111111 1e 118 On pus X. dude and 75 gms. (0.25 mole) of Primene JMT diluted Unmhibitedfuelblendp1uSEX 3 25 7 with 345 gms. of Process 011 #5 was stirred at 95 C. for Uninhibited mu blend plus Ex. 4- 50 5 2 hours to form the Primene JMT maleamic acid. The $223 $3: 2: 2g 8 Primene JMT maleamic acid was then added at room Uninhibited fuelblend plus EX. '1--- 50 4 temperature with stirring to the zinc methylate solution glggg gig: 3: E8 ii prepared by reacting 11.5 gms. (0.5 mole) of sodium in Uninhibited fuel blend plus Ex. 50 o the form of a sodium methylate solution with 36 gms. (0.25 mole+2 grns. excess) of zinc chloride dissolved in 250 cc. of methanol. The mixture was gradually heated with stirring to distill out the methanol. The mixture became thick at about 85 C. at which a quantity of 6 cc. of water was added dropwise. The reaction mixture fluidized and was gradually heated to 150 C. The reaction product was allowed to settle and filtered through Hyflo clay. The final product, the zinc salt of Primene JMT maleamic acid, which contained 75% Process oil #5, was clear and fluid at room temperature.

Analysis A mixture of 32.7 gms. 6 mole) of maleic anhydride, 65 gms. mole) of Armeen 12D and 204 gms. of xylene as diluent was stirred at 95 C. for 2 hours to form the Armeen 12D maleamic acid. To the Armeen 12D maleamic acid was added at room temperature with stirring 4 gms. (Ms mole) of magnesium in the form of a magnesium methylate solution. The mixture was gradually heated to 135 C. to distill out the methanol. The reaction product was filtered through Hyflo clay. The final product, the magnesium salt of Armeen 12D maleamic acid, which contained 66 /s% xylene, was clear and fluid when still warm, but gelled at room temperature.

In the following Table I, data are set forth showing the results obtained by subjecting to the following screenclogging test, a base fuel oil with and without the addition agents embodied herein.

Screen clogging The anti-screen clogging characteristics of a fuel oil.

were determined as follows: The test is conducted using Then, the sludge deposit on the screen is washed off with 1 normal pentane and filtered through a tared Gooch crucible. After drying, the material in the Gooch crucible is washed with a 50-50 (volume) acetone-methanol mixture. The total organic sediment is obtained by evaporating the pentane and the acetone-methanol filtrates. Drying and weighing the Gooch crucible yields the amount of inorganic sediment. The sum of the organic and inorganic deposits on the screen can be reported in milligrams recovered or converted into percent screen clogging.

TABLE I.SCREEN CLOGGING TEST [Inhibitors blended in a fuel oil blend comprising 60% catalytically cracked component and 40% straight run componentapproximately As is apparent from the data in Table I, the addition agents embodied herein are markedly eifective for inhibiting the screen-clogging characteristics of fuel oils.

In the following Table II, data are set forth showing the results obtained by subjecting to the following sedimentation test, a base fuel oil with and without the addition agents embodied herein.

Sedimentation The test used to determine the sedimentation characteristics of the fuel oils is the 110 F. Storage Test. In this test, a SOD-milliliter sample of the fuel oil under test is placed in a convected oven maintained at 110 F. for a period of 12 weeks. the oven and cooled. The cooled sample is filtered through a tared asbestos filter (Gooch crucible) to remove insoluble matter. The weight of such matter in milligrams is reported as the amount of sediment. A sample of the blank, uninhibited oil is run along with a fuel oil blend under test. The effectiveness of a fuel oil containing an inhibitor is determined by comparing the weight of sediment formed in the inhibitor oil with that formed in the uninhibited oil.

TABLE II.EUEL OIL STORAGE TESTS [Inhibitors blended in a fuel oil blend comprising 60% catalytically cracked component and 40% straight run component-approximately 320-640 F. boiling range] Cone, Sediment, Inhibitor lb./1,000 mgJliter bbls.

Uninhiblted fuel blend 0 70 Uninhibited fule blend plus Ex 50 15 Uninhibited fuel blend 0 s1 Uninbibited fuel blend plus Ex. 50 35 Uninhibited fuel blend 0 72 Uninhibited fuel blend plus Ex. 3... 50 8 Uninhibited fuel blend 0 72 Uninhibited fuel blend plus Ex. 50 18 Uninhibited fuel blend 0 72 Uninhibited fuel blend plus 50 13 Uninhibited fule blend 0 72 Uninhibited fuel blend plus Ex. 50 24 Uninhibited fule blend 0 137 Uninhiblted fuel blend plus Ex. 9... 50 48 Uninhibited fuel blend 0 6 Uninhibited fuel blend plus Ex. 10 25 4 Then, the sample is removed from As is apparent from the data in Table II, the addition agents embodied herein inhibit the tendency of fuel oils against sedimentation on prolonged storage.

In the following Tables III and IV, data are shown for, respectively, the results of tests of (a) a fuel oil with and without the addition agents embodied herein, and (b) a light turbine oil with and Without the addition agents embodied herein to determine the effectiveness of the addition agents as anti-rust agents. Such tests were carried out under the conditions of ASTM Rust Test D-665, operated at 48 hours at 80 F., using distilled water.

TABLE III.-ASTM RUST TEST D-665 [Inhibitors blended in a fuel oil blend comprising 60% catalytically cracked component and 40% straight run componentapproximately 320-640" F. boiling range] Cone, Rust Inhibitor p.p.1n. Test Result Blank fuel blend Fail. Blank fuel blend plus Ex. 1. 50 Pass. Blank fuel blend plus Ex. 3- 10 D0. Blank fuel blend plus Ex. 4 25 Do. Blank fuel blend plus Ex. 5 Do. Blank fuel blend plus Ex. 7.-. 25 Do. Blank fuel blend plus Ex. 9. 25 D0. Blank fuel blend plus Ex. 10 25 Do.

TABLE IV.-ASTM RUST TEST D-665 [Inhibitors blended in alight turbine oil] Cone, Rust Inhibitor Test percent Result Blank light turbine oil 0 Fail. Blank light turbine oil plus Ex. 0. 3 Pass. Blank light turbine oil plus Ex. 0.3 Do. Blank light turbine oil plus Ex. 0.2 Do. Blank light turbine oil plus Ex. 0.3 Do. Blank light turbine oil plus Ex. 0.2 Do. Blank light turbine oil plus Ex. 0.4 Do.

As is apparent from the data in Tables III and IV, the addition agents of this invention effectively inhibited the fuel oils against rusting.

Over and above the aforesaid improvements imparted to mineral oil compositions by the addition agents embodied herein, such addition agents also function as inhibitors against objectionable emulsification. In that respect, the presence of the tertiary carbon atom linked to the nitrogen atom in the alkyl grouping of the metal salts embodied herein is important as, when corresponding metal salts, but in which the nitrogen atom is linked to a normal primary aliphatic group, such salts induce severe emulsification with water. Thus, reference is made to Example 11 showing preparation of a magnesium salt of maleamic acid derived from Armeen 12D, which is a mixture of primary straight-chain amines as hereinbefore described. To illustrate the importance of a tertiary carbon atom linked to the nitrogen atom in the additives embodied herein for inhibiting emulsification, fuel oil compositions were prepared by (1) addition of the metal salt of Example 1 at a concentration of 25 lbs./ thousand barrels of a fuel oil as used for the aforedescribed fuel oil tests and (2) addition in the same concentration in such a fuel of the metal salt of Example 11, and such fuel oil compositions were subjected to the following emulsion test:

Emulsion test The procedure for the fuel oil emulsion test is as follows: a 200 milliliter portion of the fuel to be tested and milliliters of distilled water are placed in a clear glass pint bottle. The bottle is tightly capped and set in an Everbach mechanical shaker in a horizontal position such that the maximum degree of agitation is afforded. The shaker is run at its maximum setting for 5 minutes. The bottle is then removed and allowed to stand in an upright position in the dark for 24 hours. At the end of the 24 hour settling period, the appearance of the water layer is noted. The fuel layer is siphoned off, care being taken not to disturb the oil-water interface, and is discarded. A fresh portion of the fuel oil being tested is then added. The described sequence of steps is repeated. If no emulsion appears in the Water layer after this sequence has been performed ten times, the oil is considered to have passed the test. On the other hand, if,'after any 24 hour settling period in the procedure, there is any degree of emulsification in the water layer, the fuel is considered to have failed the test. This test procedure has been found to provide emulsions in inhibited oils similar to emulsions which occur in these same oils only after prolonged periods of normal handling and storage in the field on a commercial basis.

0 Clean break on the interface of oil and water. No dirt, skin, or bubbles present.

l Very slight skin at the oil-water interface that usually does not break on tilting the bottle.

2 Skin at oil-Water interface, heavier than #1 and usually accompanied with dirt and bubbles on the skin. No evidence of any white emulsion.

3 First sign of white emulsion. Usually forms at the bottom and in the center of the bottle. It is circular in shape and approximately to 1 inch in diameter.

4 Approximately the same amount of emulsion on the bottom of the bottle as #3. However, emulsion is also beginning to form at oil-water interface and extends to downward into the water layer. Roughly 15% of Water layer occupied by emulsion.

5 Circular emulsion at bottom of bottle extends outward and upward resembling spokes. Emulsion at the interface a little thicker than #4.

6 More emulsion than #5. Thin film of emulsion forming on sides of bottle surrounding the water layer. Water is still visible looking through the sides and looking up from the bottom of the bottle.

7 Emulsion on bottom of Water layer is almost solid. Emulsion on sides of bottle is broken in a feW spots enabling the operator to see the water layer.

8 Semi-solid emulsion with perforations or bubbles similar to a honeycomb. No

The results obtained from the foregoing emulsion test were as follows:

TABLE V.EMULSION TEST [Inhibitors blended in a fuel oil blend comprising 60% catalytieally cracked component and 40% straight run cornponentapproxirnately 320640 F. boiling range] Cone, Test Inhibitor lb./l.000 Result bbls.

Uninhibited fuel blend plus Ex. 1 25 l Uninhibited fuel blend plus Ex. 11 25 1O It is apparent from the foregoing that the magnesium salt of Primene 81R maleamic acid (Ex. 1) containing a tertiary carbon atom attached to the nitrogen atom effectively inhibited emulsification (Rating 1), whereas the corresponding magnesium salt (Ex. 11), but prepared from primary straight-chain amines (Armeen 12D), resulted in a composition that emulsified severely (Rating Although the present invention has been described with preferred embodiments, it is to be understood that variousmodifications and adaptations thereof may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand.

We claim:

1. A liquid mineral oil containing a small amount sufficient to inhibit corrosion of said oil of a divalent metal salt of the reaction product of maleic anhydride and a mixture of aliphatic hydrocarbyl primary branchedchain amines having from about 4 to about 30 carbon atoms per molecule.

2. A composition as defined in claim 1, wherein the mineral oil is a distillate fuel oil.

3. A composition as defined in claim 1, wherein the mineral oil is a lubricating oil.

4. A composition as defined in claim 1, wherein the metal is a divalent metal of the group consisting of magnesium, barium, calcium, zinc and strontium.

5. A composition as defined in claim 1, wherein the mineral oil is a distillate fuel oil having an initial boiling point of at least about 100 F. and an end boiling point not higher than about 750 F. and boiling substantially continuously throughout its distillation range.

6. A liquid mineral oil containing from about 1 to about 200 pounds, per thousand barrels of said oil, of a divalent metal salt of the reaction product of maleic anhydride and a mixture of aliphatic hydrocarbyl primary branchedchain amines having from about 4 to about 30 carbon atoms per molecule.

7. A liquid mineral oil containing from about 1 to about 200 pounds, per thousand barrels of said oil, of a divalent metal salt of the reaction product of maleic-anhydride and a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino group and having from about 12 to about 24 carbon atoms per amine molecule.

8. Aliquid mineral oil containing from about 1 to about 200 pounds, per thousand barrels of said oil, of a divalent metal salt of the reaction product of maleic anhydride and a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino group and having from about 12 to about 15 carbon atoms per amine molecule.

9. A liquid mineral oil containing from about 1 to about 200 pounds, per thousand barrels of said oil, of a divalent metal salt of the reaction product of maleic anhydride and a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino group and having from about 18 to about 24 carbon atoms per amine molecule.

10. A divalent metal salt of the reaction product of maleic anhydride and a mixture of aliphatic hydrocarbyl primary branched-chain amines having from about 4 to about 30 carbon atoms per molecule.

11. The compound of claim 10 wherein the metal is a divalent metal of the group consisting of magnesium, barium, calcium, zinc and strontium.

12. A divalent metal salt of the reaction product of maleic anhydride and a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino group and having from about 12 to about 24 carbon atoms per amine molecule.

13. A divalent metal salt of the reaction product of maleic anhydride and a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino group and having from about 12 to about 15 carbon atoms per amine molecule.

14. A divalent metal salt of the reaction product of maleic anhydride and a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino group and having from about 18 to about 24 carbon atoms per amine molecule.

References Cited by the Examiner UNITED STATES PATENTS 2,699,427 1/ 1955 Smith et al 44-68 X 2,977,309 3/1961 Godfrey et al. 252-515 3,046,102 7/1962 Andress et al. 25233.6 X

DANIEL E. WYMAN, Primary Examiner. 

1. A LIQUID MINERAL OIL CONTAINING A SMALL AMOUNT SUFFICIENT TO INHIBIT CORROSION OF SAID OIL OF A DIVALENT METAL SALT OF THE REACTION PRODUCT OF MALEIC ANHYDRIDE AND A MIXTURE OF ALIPHATIC HYDROCARBYL PRIMARY BRANCHED CHAIN AMINES HAVING FROM ABOUT 4 TO ABOUT 30 CARBON ATOMS PER MOLECULE. 